1. Field of the Invention
The present invention relates to a fuel cell system capable of controlling a pressure of a gas in a fuel cell and a method of controlling the pressure of the gas in the fuel cell, and particularly to a fuel cell system with overpressure protection for a membrane in the fuel cell and a method of controlling the pressure of the gas in the fuel cell to protect overpressure in the membrane of the fuel cell.
2. Description of the Related Art
Fuel cell systems used in fuel cell electric vehicles (FCEV) include a plurality of single cells stacked, each cell being configured by sandwiching a solid polymer electrolyte membrane with an anode electrode and a cathode electrode in which hydrogen is supplied from a hydrogen tank to the anode electrode as fuel, and air is supplied to the cathode electrode through an air compressor. In an exhaust side of the cathode electrode is provided an air back pressure valve (air pressure valve). A pressure of the air supplied in the cathode electrode is controlled toward a target pressure by controlling a rotational speed of the air compressor and a valve position of the air back pressure valve.
This type of fuel cell system is disclosed, for example, in Japanese laid-open patent application publication No. 2003-168467 at paragraphs from 0026 to 0029, and FIG. 1.